Spawning behavior in Nocomis effusus
is described from direct observations and review of videotapes made in
Yellow Creek (Cumberland River drainage), Tennessee in 2003. Nest
construction (i.e., excavating a concavity, forming a platform, and
building a mound), and spawning behavior in N. effusus where a single breeding
male excavates a pit and spawns with females on the upstream slope of
his nest is like that described for Nocomis asper and Nocomis biguttatus. In
digging a spawning pit, a male N.
effusus reshapes and reorganizes substrate materials that
results in spawning areas on the upstream slope of the nest composed of
6.0 and 11.3 mm size-class pebbles. Aggressive behaviors (in
order of increasing aggression) observed between nest-building and
intruder male N. effusus were
non-contact head displacement, non-contact body displacement, chase,
circle swim, and head/body butt. Nest associates (i.e., species that
congregate and may spawn in a nest but do not contribute to its
construction) observed over nests of N.
effusus were Luxilus
chrysocephalus and Lythrurus
fasciolaris.
Keywords: Nocomis effusus,
nest-building, spawning behavior